Biology subjects

Rose, P.

Publications and source records attributed to Rose, P..

4 recordsLinked to original sources

bioRxiv2025

Cysteine Reactivity Profiling Illuminates Monoclonal Antibody Disulfide Bond Reduction Mechanisms in Biopharmaceutical Process Intermediates

Monoclonal antibodies (mAbs) are crucial biotherapeutics with increasing global demand, but their production can be impacted by the reduction of disulfide bonds. This study presents a chemical proteomics workflow aimed at elucidating the mechanisms underlying disulfide bond reduction in mAbs produced from Chinese hamster ovary (CHO) cells. We employed iodoacetamide-desthiobiotin (IA-DTB) and the parallel accumulation and serial fragmentation combined with data-independent acquisition (diaPASEF) methodology for cysteine reactivity profiling and successfully quantified approximately 4,500 cysteine-containing peptides from harvested cell culture fluids (HCCF). Our findings reveal that various protein disulfide oxidoreductases were active in reducing HCCF, offering critical insights into the redox environment affecting mAb stability. Notably, we quantified specific cysteine residues in enzymes such as glutaredoxin and thioredoxin domain-containing protein 12, suggesting potential links between their activity to disulfide bond dynamics. This workflow not only complements conventional abundance proteomics but also enhances the understanding of functional enzyme states in bioprocessing. Ultimately, our approach provides a promising strategy for enzymes contributing to disulfide bond reduction, paving the way for improved manufacturing processes of mAbs.

bioengineering↗

bioRxiv2020

Disruption of the gut microbiota attenuates epithelial ovarian cancer sensitivity to cisplatin therapy

Epithelial Ovarian Cancer (EOC) is the leading cause of gynecologic cancer death. Despite many patients achieving remission with first-line therapy, up to 80% of patients will recur and require additional treatment. Retrospective clinical analysis of OC patients indicates antibiotic use during chemotherapy treatment is associated with poor overall survival. We assessed whether antibiotic (ABX) therapy would impact growth of EOC and sensitivity to cisplatin in murine models. Immune competent or compromised mice were given control or ABX containing water (metronidazole, ampicillin, vancomycin, and neomycin) before being intraperitoneally injected with murine EOC cells. Stool was collected to confirm microbiome disruption and tumors were monitored, and cisplatin therapy was administered weekly until endpoint. EOC tumor-bearing mice demonstrate accelerated tumor growth and resistance to cisplatin therapy in ABX treated compared with nonABX treatment. Stool analysis indicated most gut microbial species were disrupted by ABX treatment except for ABX resistant bacteria. To test for role of the gut microbiome, cecal microbiome transplants (CMTs) of microbiota derived from ABX or nonABX treated mice were used to recolonize the microbiome of ABX treated mice. nonABX cecal microbiome was sufficient to ameliorate the chemoresistance and survival of ABX treated mice indicative of a gut derived tumor suppressor. Mechanistically, tumors from ABX treated compared to nonABX treated mice contained a high frequency of cancer stem cells that were augmented by cisplatin. These studies indicate an intact microbiome provides a gut derived tumor suppressor and maintains chemosensitivity that is disrupted by ABX treatment. SignificancePlatinum resistance is associated with poor prognosis and reduced therapeutic options for ovarian cancer patients. We identifed a tumor suppressive role of the gut microbiome that is disrupted upon antibiotic therapy.

cancer biology↗

bioRxiv2020

Feeding dihydroquercetin and vitamin E to broiler chickens reared at standard and high ambient temperatures

The use of natural antioxidants, in particular polyphenols such as dihydroquercetin (DHQ), in animal nutrition have recently increased in popularity. This may partly be due to the risk of increased incidences of heat stress associated with raising livestock in warmer ambient temperatures, facilitated by global warming, reducing antioxidant capacity. The current research demonstrates the effect of dietary DHQ, vitamin E and standard or high ambient temperatures on growth performance, energy and nutrient metabolism, gastrointestinal tract development (GIT), jejunal villus morphometry and antioxidant status in broiler chickens. Each of the four experimental diets were fed to 16 pens of five birds, which were allocated to four rooms (four pens in each room). The temperature in two rooms was maintained at a constant 35 {degrees}C (high temperature; HT), and the temperature in the other two rooms was gradually reduced from 27 {degrees}C at 7d of age to 22 {degrees}C at 20d of age (standard temperature; ST). Rearing birds at HT reduced: feed intake, weight gain, weight of small intestine, total GIT, liver, spleen, heart, villus height, villus surface area and lowered blood glutationperoxidase (GSH-Px). Dietary DHQ increased blood GSH-Px and total antioxidant status, increased heart weight and reduced caecal size. When fed separately, DHQ and vitamin E improved hepatic vitamin E concentration. Feeding vitamin E increased spleen and liver weights. When fed together, DHQ and vitamin E reduced villus height, villus height to crypt depth ratio and villus surface area. Temperature and antioxidants did not affect energy and nutrient metabolism. There were no effects of dietary antioxidants on growth performance of broiler chickens and there were no mortalities. At present it is unclear if feeding antioxidants (in particular DHQ) at different levels, using different dietary formulations, and rearing birds under a range of environmental conditions may be effective at enhancing production performance and bird health in hot ambient climates.

physiology↗

bioRxiv2018

A domestication history of dynamic adaptation and genomic deterioration in sorghum

The evolution of domesticated cereals was a complex interaction of shifting selection pressures and repeated introgressions. Genomes of archaeological crops have the potential to reveal these dynamics without being obscured by recent breeding or introgression. We report a temporal series of archaeogenomes of the crop sorghum (Sorghum bicolor) from a single locality in Egyptian Nubia. These data indicate no evidence for the effects of a domestication bottleneck but instead suggest a steady decline in genetic diversity over time coupled with an accumulating mutation load. Dynamic selection pressures acted sequentially on architectural and nutritional domestication traits, and adaptation to the local environment. Later introgression between sorghum races allowed exchange of adaptive traits and achieved mutual genomic rescue through an ameliorated mutation load. These results reveal a model of domestication in which genomic adaptation and deterioration was not focused on the initial stages of domestication but occurred throughout the history of cultivation.

evolutionary biology↗